


my best laid plan

by astralpenguin



Category: Death Note & Related Fandoms, Death Note (Anime & Manga)
Genre: Alternate Universe - Canon Divergence, Alternate Universe - Soulmates, Asexual Character, Asexual Yagami Light, Demiromantic Yagami Light, Enemies to Lovers, Getting Together, Greyromantic Yagami Light, M/M, Soulmate-Identifying Marks, Soulmates, Yagami Light is Kira, kind of
Language: English
Status: Completed
Published: 2020-08-17
Updated: 2020-08-17
Packaged: 2021-03-05 23:20:27
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,771
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25953601
Author URL: https://archiveofourown.org/users/astralpenguin/pseuds/astralpenguin
Summary: He was in the shower when he saw it.Just grazing the top of his left hip bone was a line of text that hadn’t been there the previous morning.‘I didn’t think it would actually happen.’When someone lies to their soulmate, their lie is written on their soulmate's skinThis causes problems for Kira
Relationships: L/Yagami Light
Comments: 87
Kudos: 674





	my best laid plan

**Author's Note:**

> this au idea was perfect for these two okay

He was in the shower when he saw it.

Just grazing the top of his left hip bone was a line of text that hadn’t been there the previous morning.

_‘I didn’t think it would actually happen.’_

Light knew two things at once.

The first was something that he’d already guessed for himself. L had gone into the live broadcast yesterday expecting Lind L Tailor to die. Anything he’d said to the contrary had only been said so that he wouldn't get attacked for using the life of another to shield his own.

The second was that L was his soulmate.

  
  


Light first learnt about soulmates when he was ten years old. His family was on holiday, and his little sister spotted a line of text snaking up the back of their mother’s leg. Sayu being Sayu, she asked about it right then and there, and their mother being their mother, she answered honestly.

“Most people have a soulmate,” she said. “Some people have more than one, but I only have one. Every time someone’s soulmate lies to them, whatever was said is written on their body.”

“Does it ever come off?” Sayu asked.

Their mother shook her head. “Some people choose to cover them up for many different reasons. But no. The lies themselves will never fade.”

The text on their mother’s leg read: _‘We’d be better off without each other.’_

“Is Dad your soulmate?” asked Sayu.

Their mother nodded. “Yes, he is. I’m very lucky that I found my soulmate early, and I get to spend my life with him. Not everyone is so fortunate.”

(Thinking back on this now, Light knew that his mother had been more right that she could ever know.)

  
  


It changed nothing.

Even if they were soulmates, L still had to die.

Light’s new world, his Godhood, it was all too important.

He hadn’t expected to have a soulmate in the first place. If he proceeded as if that text wasn’t there, as if he didn’t have a soulmate, then nothing would change.

He didn’t need a soulmate.

He didn’t want a soulmate.

He was better off without a soulmate.

(Maybe if he told himself that enough times, it would become the truth.)

  
  


Some people were obsessed with finding their soulmates. Sayu was one of these people. Every time she met someone new, no matter who it was and no matter how brief their interaction would be, she would declare herself to be the Empress of Saturn, or something like that.

She hadn’t found her soulmate yet, but she didn’t mind. She was only fourteen. She had plenty of time.

Light knew that whoever her soulmate ended up being, Sayu would be happy.

Soulmates could be romantic and soulmates could be platonic. There were no hard and fast rules for how soulmate relationships had to play out.

Some people didn’t like to date, preferring to wait for their soulmates. Some people did like to date, for a multitude of reasons. Their soulmate could be platonic, and then what would’ve been the point in waiting for them? Or if their soulmate was their soulmate, then they surely wouldn’t mind them having a dating history. Or maybe they just wanted to. Not everyone put a huge amount of thought into why they did what they did.

Light was the object of many people’s affections, but he didn’t date.

It never had anything to do with his soulmate, even before he knew who his soulmate was.

There was just never anyone he liked.

On the rare occasions that he agreed to go out with someone for an afternoon, he always made it clear to them that there was no chance of it turning into something serious. People assumed that he was waiting for his soulmate, and he didn’t feel any need to correct them

Let them believe what they want.

It didn’t matter to him.

  
  


_“I’m not Kira.”_

He realised his mistake as soon as he said it, but it was too late.

The words were already out there.

If this was indeed the real L, then the marks were already somewhere on his skin.

Light’s Kingdom would fall, and all it had taken was a moment of thoughtlessness and three measly words.

But L never brought it up.

(He had the proof he needed. Why didn’t he act on it?)

  
  


_“There were actually four photos.”_

Light scowled as he heard L say it.

A lie.

Another lie.

Another mark on his skin to remind him of his weakness.

(Alternatively, another mark on his skin to remind him of what he was going to lose.)

He wondered where the words would be written. He hoped that they wouldn’t be too prominent.

(They were in a ring around his right ankle. He supposed this was acceptable.)

  
  


“Lie to me!”

Misa was halfway out the door when she stopped and said that.

She had already demonstrated a high enough level of impulsiveness and obsession with him that he couldn’t predict how she’d react if he told her the truth. The truth being that he already knew that they weren’t soulmates. That there’d been enough lying through the tapes sent into Sakura TV that, if they were soulmates, they’d have been marked as such already. That the soulmate marks he _did_ have weren't from her.

If she attacked him over it he wouldn’t be surprised.

The simplest course of action, he realised, was to do as she had asked.

“I ate all the apples.”

She smiled, replied with, “I’ve known you all my life,” before leaving.

She’d lied to him in return, though Light was sure that she wished it was the truth.

He shuddered.

Later she’d realise that her skin was still blank, and that Light wasn’t hers, but for now she had left him alone.

That was all he wanted from her.

That and L’s head.

  
  


Light said it again, _“I’m not Kira,”_ and if L understood the significance of it, he didn’t show it.

  
  


Maybe L never took his clothes off.

Maybe L wanted to catch Kira fairly, and didn’t view snitching soulmate marks as being fair.

Maybe L was Light’s soulmate, but Light wasn’t L’s.

(Light didn’t know which possibility was worse.)

  
  


_“You are the first friend that I’ve ever had.”_

The words appeared above his heart, and Light didn’t understand why the sight of them made him want to cry.

Gods didn’t cry.

(He thought back to his reply, how it hadn’t been a lie, and hoped that L would choke on it.)

  
  


_“I might be Kira,”_ he said as he handed himself in, and as he was blindfolded and taken elsewhere, he took a moment to wonder.

If he knew for certain that he was Kira, would saying that he _might_ be Kira be enough of a lie to count?

(In his gut he knew that it was.)

  
  
  


He saw it on the third day of them being handcuffed together.

L had come out of the shower.

His shirt was off, a towel was on his head, and he had his back turned towards Light.

And on his back, where L could very easily never see for himself, there was writing.

_‘I’m not Kira.’_

_‘I’m not Kira.’_

_‘I’m not Kira.’_

Over and over again until, right at the base of his spine, read a slight variation.

_‘I might be Kira.’_

Light remembered saying these things.

He didn’t remember them being lies.

(Now that he thought about it, there was a lot that he didn’t remember.)

  
  


He told L about what he’d seen.

He knew that he wouldn’t be able to live with himself if he didn’t.

  
  


There was no way that Kira could benefit from L finding undeniable evidence that they and Light were once one and the same.

If Light was Kira, then he would accept the consequences. He didn’t expect any leniency just because L was his soulmate. He didn’t _want_ any leniency for this.

Kira had to be stopped. No ifs, no buts, no anything.

If stopping Kira meant his own death, then so be it.

(He wanted to help catch whoever was acting as Kira now, but he didn’t expect to get what he wanted.)

  
  


L brought in Watari.

“Say it,” he said to Light.

“I’m not Kira.”

And Watari confirmed that no new lines of text had appeared on L’s back.

What had once been a lie was now the truth.

  
  


(They didn’t tell the others, and Light was allowed to stay on the case.)

  
  


_“I’m tired.”_

“Not according to my left arm, you’re not.”

Light laughed.

“Okay,” he said. “But you haven’t slept in three days and that can’t be healthy.”

“It’s not,” L agreed.

They went to bed, and for once L slept.

  
  


If you’d asked Light what they were fighting about, he wouldn’t have been able to tell you.

What they were fighting about didn’t matter.

(It never mattered.)

What _did_ matter was how the fight ended.

_“I hate you!”_

The words appeared immediately on L’s wrist, peeking out from under the handcuff.

“No you don’t,” he said.

“No,” said Light, sinking down onto the end of the bed. “I don’t.”

“Why would you say that you hate me if it’s not the truth?”

“Because I’m angry,” he said.

“Because I’m overreacting,” he said.

“Because nobody else has ever made me feel the way you do,” he said.

“Because I like you more than I should.”

(“More than you should? We’re literally soulmates.”

“That doesn’t actually mean anything.”

“You’re right. It doesn’t.”)

(“If it helps, I like you more than I should too.”)

(It helped.)

  
  


“It’s a shame about Aizawa,” said Light.

“Yes,” said L.

“Although,” said Light, “you were unnecessarily cruel.”

“I was,” said L. “If I could do today over again, I wouldn’t try to test him. It didn’t help anything.”

Light nodded. “Good.” He sat on the bed. “But don’t take all of what he said too personally. I think he just missed his family, and was taking it out on you.”

“I agree, although it is my fault he hasn’t seen much of his family, so him taking it out on me is fair enough.”

Light shrugged. “I don’t know if I’d entirely agree with that. He should’ve had some idea of what to expect when he signed up for this.”

“Do you miss your family?”

 _“No,”_ he said, and then he realised it wasn’t true.

He shrugged it off.

Of course he missed his family. He loved his mother, and once upon a time he and his sister had been extremely close.

Now it had been months since he’d heard from either of them.

He didn’t expect L to understand, and to answer his question honestly would lead to a conversation that he didn’t want to have.

L could discover the truth for himself later.

They didn’t need to talk about it.

(When L handed him a phone and instructed him to call home, Light didn’t need telling twice.)

  
  


“I wanted to kiss you earlier.”

Light nearly dropped his toothbrush.

He turned to face L, allowing his face to show the questions he had.

L stood at the bathroom door. There was plenty of distance between them.

“Your handling of the Yotsuba group was superb. You acted faster than I was able to, and now we have someone on the inside and we’re in a much better position. I wanted to kiss you.” His eyes stared deeply into Light’s. “I still do.”

Light blinked. He held up a finger to tell L to hold that thought, turned back to the sink, and finished brushing his teeth.

Then he crossed the room and kissed him.

At some point, they found their way to the bed. They spent what felt like hours just lying there, kissing lazily and talking about nothing of any importance.

“I’m not interested in sex,” Light eventually said, because if this was happening then L needed to know.

“Okay,” said L. “We won’t have sex.”

Light didn’t know what he’d expected L’s reaction to be, but he did know that of all the possible outcomes, this was one of the best.

For a short while he forgot all about Kira.

He fell asleep in L’s arms, and he was happy.

(He should’ve known better than to expect it to last.)

  
  


“Are you alright?” L asked as they settled in the helicopter.

Light nodded. _“Yeah,”_ he said.

It wasn’t true.

He was terrified.

If Kira - the Kira that had once been _him_ \- had planned his return, then today would be when it happened. If he knew himself at all, then it was bound to happen without L even noticing, or being able to prove anything.

Telling L the truth now, that he thought the first Kira would take him over before the day’s end, would derail their plan to catch the third, and that wasn’t something they could afford to do.

But any lies he told would be written on L’s skin forever.

Forever was a long time.

“You should Kira-test me again tomorrow,” he said.

L tilted his head to the side in question. “Kira-test?”

“Get me to say I’m not Kira, and check if any new marks appear,” he said. “Focus on Higuchi for now, but please do this for me tomorrow.”

Understanding washed over L’s face, and he nodded. “I will.”

(He touched the notebook, and the last thing he felt before being pushed to the back of his own mind was relief.

L would do as he’d asked.)

  
  
  


Light had been in this exact position before.

No, that wasn’t right.

His memoryless self had been in this position, and for _him_ what he was being made to say had been true.

His memoryless self was the reason that L had noticed the writing on his back in the first place.

But now he was here, and it wasn’t true anymore, and the moment he said it he would be irrevocably exposed.

Where the hell was Rem?

Without Rem, he didn’t see a way out of this. No matter what his next action was, there wasn’t a single outcome where he didn’t get caught.

He took a deep breath.

He was out of time.

_“I’m not Kira.”_

(The letters formed at the base of L’s neck, at the top of the list of all the other times he’d said it. He closed his eyes at the sight of it.)

  
  


Rem, it turned out, had been told that Misa would be safe so long as she never killed again. Rem had accepted this arrangement.

  
  


L made Light tell him which of the rules were real and which ones weren’t. He also made Light tell him where the other notebook was hidden.

Light tried to keep the other notebook’s location to himself, but once he was reminded that, if he didn’t let them retrieve it, then _anyone_ could find and use it, he relented. Better that law enforcement have the notebook than some random criminal.

Once L was satisfied with the answers, he nodded to Watari.

Who then put a match to the notebook.

Helpless, all Light could do was watch as his most prized possession went up in flames.

(He came back to himself, and he didn’t know where he was. Why were his wrists bound? What was he watching burn? 

Why was L looking at him like that?)

(L explained everything.)

  
  
  


Light went with L and Watari to retrieve the other notebook, but he stood well back when the box was uncovered.

L and Watari both wore gloves as they examined the box’s contents so as to not take ownership of the notebook inside, but Light wasn’t willing to take even that much of a risk.

Kira had to stay gone.

A piece of paper fell out of the notebook. Light asked what it was, and got the reply that it was a letter to Misa, instructing her to kill L.

“I’m sorry,” said Light.

“Don’t be,” said L. “If it weren’t for you, I probably _would_ be dead right now.”

Light simultaneously felt reassured and not reassured at all.

He supposed that him both being Kira and not being Kira was enough of a contradiction that he shouldn’t be surprised when more contradictions followed.

L and Watari burnt the notebook, and the letter that had been left with it.

It was over.

(For good this time.)

  
  


(L’s fingers intertwined with his.

“Come to England with me?”

“I want to finish my undergraduate degree here. But once that’s done, yes, I will come to England with you.”

L’s smile was one of Light’s favourite things to see.)

**Author's Note:**

> please comment !! even just a smiley face will mean the world to me :D
> 
> you can find me on [tumblr!](https://astralpenguin.tumblr.com/)


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